Method for enhancing degradation performance of lignin-degrading bacteria

Abstract

A method for enhancing the degradation performance of lignin-degrading bacteria Erwinia sp. QL-Z3 and a culture medium for culturing the bacteria. The rate of degradation of an Erwinia sp. QL-Z3 strain to lignin is optimized from 14.23% before optimization to 25.01%. Under the conditions that the initial pH value of the culture medium is 8, the nitrogen source is NH4NO3, and the addition amount of lignin is 3 g/L, the activity of an LiP enzyme can be optimized to 371.00 U/L, which is 3.53 times that before optimization. When the initial pH value of the culture medium is 9.5, the nitrogen source is NH4NO3, and the concentration of lignin is 2.5 g/L, the activity of MnP and Lac enzymes can be optimized to 839.50 U/L and 219.00 U/L, respectively, which are 3.18 and 2.84 times that before optimization.

What is claimed is: 
     
         1 . A method for enhancing degradation performance of lignin degradation bacteria, wherein the lignin degradation bacteria are  Erwinia  sp. QL-Z3 strain, and activated  Erwinia  sp. QL-Z3 strain are inoculated into lignin liquid medium at 30° C. and 180 rpm for cultivation;
 pH of the lignin liquid medium is 5, nitrogen source is (NH 4 ) 2 SO 4 , and lignin addition amount is 1.5 g/L; 
 components and contents of each 1 L of the lignin liquid medium are: 1.5 g of Lignin, 2 g of K 2 HPO 4 , 0.3 g of MgSO 4 ·7H 2 O, 0.08 g of CaCl 2 , 0.05 g of FeSO 4 ·7H 2 O, 0.02 g of MnCl 2 , 2 g of (NH 4 ) 2 SO 4 . 
 degradation rate of the lignin by the  Erwinia  sp. QL-Z3 strain is optimized to 25.24%; 
 by adjusting pH of the lignin liquid medium to 8, nitrogen source to NH 4 NO 3 , and lignin addition amount to 3 g/L, enzyme activity of the lignin peroxidase in the  Erwinia  sp. QL-Z3 strain is optimized to 371.00 U/L; 
 by adjusting pH of the lignin liquid medium to 9.5, the nitrogen source to NH 4 NO 3 , and the lignin addition amount to 2.5 g/L, the enzyme activity of the laccase in the  Erwinia  sp. QL-Z3 strain is optimized to 219.00 U/L; 
 by adjusting the pH of the lignin liquid medium to 9.5, the nitrogen source to NH 4 NO 3 , and the lignin addition amount to 2.5 g/L, the enzyme activity of the manganese peroxidase in the  Erwinia  sp. QL-Z3 strain is optimized to 839.50 U/L; 
 the GenBank accession number of 16SrRNA gene in the  Erwinia  sp. QL-Z3 strain is MH828331, and the GenBank accession number of the whole gene sequencing is CP037950. 
 
     
     
         2 . A method for enhancing enzyme activity of lignin peroxidase in lignin degradation bacteria, wherein  Erwinia  sp. QL-Z3 strain of the lignin degradation bacteria are cultivated in lignin liquid medium at 30° C. and 180 rpm, and the enzyme activity of the lignin peroxidase in the  Erwinia  sp. QL-Z3 strain is optimized to 371.00 U/L;
 the medium is a lignin liquid medium, pH of the lignin liquid medium is 8, nitrogen source is NH 4 NO 3 , and lignin addition amount is 3 g/L; components and contents of each 1 L of the lignin liquid medium are: 3 g of Lignin, 2 g of K 2 HPO 4 , 0.3 g of MgSO 4 ·7H 2 O, 0.08 g of CaCl 2 , 0.05 g of FeSO 4 ·7H 2 O, 0.02 g of MnCl 2 , 2 g of NH 4 NO 3 ; 
 the GenBank accession number of 16SrRNA gene in the  Erwinia  sp. QL-Z3 strain is MH828331, and the GenBank accession number of the whole gene sequencing is CP037950. 
 
     
     
         3 . A method for enhancing enzymatic activity of laccase in lignin degradation bacteria, wherein  Erwinia  sp. QL-Z3 strain of the lignin degradation bacteria are cultivated in lignin liquid medium at 30° C. and 180 rpm, and the enzymatic activity of the laccase in the  Erwinia  sp. QL-Z3 strain is optimized to 219.00 U/L;
 the medium is a lignin liquid medium, with a pH of 9.5, nitrogen source of NH 4 NO 3 , and lignin addition of 2.5 g/L; components and contents of each 1 L of the lignin liquid medium are: 2.5 g of Lignin, 2 g of K 2 HPO 4 , 0.3 g of MgSO 4 ·7H 2 O, 0.08 g of CaCl 2 , 0.05 g of FeSO 4 ·7H 2 O, 0.02 g of MnCl 2 , 2 g of NH 4 NO 3 ; 
 the GenBank accession number of 16SrRNA gene in the  Erwinia  sp. QL-Z3 strain is MH828331, and the GenBank accession number of the whole gene sequencing is CP037950. 
 
     
     
         4 . A method for enhancing enzymatic activity of manganese peroxidase in lignin degradation bacteria, wherein  Erwinia  sp. QL-Z3 strain of the lignin degradation bacteria are cultivated in lignin liquid medium at 30° C. and 180 rpm, and the enzymatic activity of manganese peroxidase in  Erwinia  sp. QL-Z3 strain are optimized to 839.50 U/L;
 the medium is a lignin liquid medium, with a pH of 9.5, nitrogen source of NH 4 NO 3 , and lignin addition of 2.5 g/L; the composition and content of each 1 L of the lignin liquid medium are: 2.5 g of Lignin, 2 g of K 2 HPO 4 , 0.3 g of MgSO 4 ·7H 2 O, 0.08 g of CaCl 2 , 0.05 g of FeSO 4 ·7H 2 O, 0.02 g of MnCl 2 , 2 g of NH 4 NO 3 ; 
 the GenBank accession number of 16SrRNA gene in the  Erwinia  sp. QL-Z3 strain is MH828331, and the GenBank accession number of the whole gene sequencing is CP037950.